Design Of Single Cell-Based Biosensor And The Analysis Of Drugs Experiment

One of the hotspots in modern biosensor research is the cell-based biosensor, which is wildly used to pharmaceutical screening, environmental monitoring, and toxin detection. There are a Varity of different measurement technologies such as FET(field effect transistor) and microelectrode, which provide an easy interface to monitor the electrical activity of the cultured cell under the exciting of drugs or electricity. This kind of sensor can not only be used to evaluate the effect of drugs through detecting the response of the cell under drugs, but also to investigate the transfer mechanical and speed of cell net. But FET and microelectrode can not be very small for the limitation of down-lead and techniques. In addition, sometimes the cell just covers one part of FFT and microelectrode, which affects the performance of sensors. But LAPS (light addressable potentiometric sensor) can choose the measurement area through the light position, and it is easy to be fabricated. So we propose a novel cell-based sensor based LAPS, which is expect to detect the response of single cell under drugs and finally evaluate the effect of drugs. The major contents and contributions of this thesis are given in the following aspects:1. By modeling of LAPS based on EIS structure and the analysis of its resolution and voltage sensitivity, we adopt a thin epi-layer of 5μm with a resistance of 10 Ω cm as the sensor substrate for the consideration of detecting single cell action potential.2. The surface of the LAPS is soaked in the phosphate-buffered saline with 100 μ g/ml poly-L-ornithine and 8μg/ml laminin to enhance the attachment of cell on LAPS, and the sensitivity of sensor is improved.3. The experiment platform mainly consists of automatic fluid injection system, observation device and detecting system. Real time recording of the signal and automation of drug delivering are acquired through programs of Data Acquisition and bump. The automation of experiment greatly reduces the jamming, thus improves the system performance.4. An Alternating current (AC) voltage with peak-to-peak amplitude of 2 mV and frequency of 1kHz as the simulated neural action potential (AP) is to investigate the sensor on detecting the AP of single living cell. The simulation signal was successfullydetected, so it makes a good promise for LAPS to measure the extracellular AP.5. The elementary experimental results show that this sensor is able to distinguish the responses of the neural cell under two concentrations of acetylcholine (lmg/1 and 10mg/l)...